Option parsing is in on the base command

lib/vagrant/commands/base.rb

@@ -1,3 +1,5 @@
+require 'optparse'
+
 module Vagrant
   class Commands
     # This is the base command class which all sub-commands must
@@ -9,8 +11,36 @@ module Vagrant
         @env = env
       end
 
+      # This method should be overriden by subclasses. This is the method
+      # which is called by {Vagrant::Command} when a command is being
+      # executed. The `args` parameter is an array of parameters to the
+      # command (similar to ARGV)
       def execute(args)
+        raise "Subcommands should implement the execute method properly."
+      end
 
+      # Parse options out of the command-line. This method uses `optparse`
+      # to parse command line options. A block is required and will yield
+      # the `OptionParser` object along with a hash which can be used to
+      # store options and which will be returned as a result of the function.
+      def parse_options(args)
+        options = {}
+        @parser = OptionParser.new do |opts|
+          yield opts, options
+        end
+
+        @parser.parse!(args)
+        options
+      rescue OptionParser::InvalidOption
+        show_help
+      end
+
+      # Prints the help for the given command. Prior to calling this method,
+      # {#parse_options} must be called or a nilerror will be raised. This
+      # is by design.
+      def show_help
+        puts @parser.help
+        exit
       end
     end
   end

lib/vagrant/commands/init.rb

@@ -2,7 +2,9 @@ module Vagrant
   class Commands
     class Init < Base
       def execute(args)
-        p args
+        parse_options(args) do |opts, options|
+          opts.banner = "Usage: vagrant init [name]"
+        end
       end
     end
   end

test/vagrant/commands/base_test.rb

@@ -0,0 +1,63 @@
+require File.join(File.dirname(__FILE__), '..', '..', 'test_helper')
+
+class CommandsBastTest < Test::Unit::TestCase
+  setup do
+    @klass = Vagrant::Commands::Base
+  end
+
+  context "initializing" do
+    should "setup the env attribute" do
+      env = mock("env")
+      instance = @klass.new(env)
+      assert_equal env, instance.env
+    end
+  end
+
+  context "instance methods" do
+    setup do
+      @env = mock_environment
+      @instance = @klass.new(@env)
+    end
+
+    context "executing" do
+      should "raise an error if called (since not a subclass)" do
+        assert_raises(RuntimeError) {
+          @instance.execute([])
+        }
+      end
+    end
+
+    context "parsing options" do
+      setup do
+        @args = []
+      end
+
+      should "return the options hash" do
+        value = mock("foo")
+        result = @instance.parse_options(@args) do |opts, options|
+          options[:foo] = value
+        end
+
+        assert_equal value, result[:foo]
+      end
+
+      should "parse with the given args" do
+        parser = mock("parser")
+
+        OptionParser.stubs(:new).returns(parser)
+        parser.expects(:parse!).with(@args)
+        @instance.parse_options(@args) do; end
+      end
+
+      should "show help if an invalid options error is raised" do
+        parser = mock("parser")
+
+        OptionParser.stubs(:new).returns(parser)
+        parser.expects(:parse!).raises(OptionParser::InvalidOption)
+        @instance.expects(:show_help).once
+
+        @instance.parse_options(@args) do; end
+      end
+    end
+  end
+end